Which way did it go? How long did it fly? Did it crash or did someone land with no one noticing? How and why and who? Seven long days after a red-eye flight from Malaysia turned into a mystery for the ages. None of those questions is answered today. And every time a new lead arises, it is contradicted or it is disputed.

But today there is a growing sense that Flight 370 with 239 passengers on board and crew members as well did, in fact, make a sharp turn to the west after it dropped off civilian radar and flew on for four or more hours. And that is based on something called pings. Pings from the plane's automated communications system trying to make contact with satellites. Normally planes, such as the Boeing 777, transmit regular streams of data about critical systems, but the last such report from this flight, Flight 370, came just minutes after takeoff.

And then there's this. Reuters is reporting that Flight 370 not only kept flying for hours, it flew in established air corridors following so-called way points. That's based on Malaysian military radar data Reuters says. It puts the jet, or what's left of it anyway, into the Indian Ocean. And well into the Indian Ocean, which is now being searched by India's air force, coast guard and navy. It's soon to be joined by a United States destroyer.

But wait. China's University of Science and Technology has got something entirely different to say. It says it recorded a, quote, sea floor event about 90 minutes and 70 miles away from Flight 370's last confirmed contact. And that is not an area given to tremors. So researchers say that it could have been a big plane crashing into the water.

And finally, speaking of seismic, late this morning, a 5.5 magnitude earthquake struck in the South Andaman Sea, about 66 miles off the Andaman and Nicobar Islands. There are no reports of damage, no reports of injuries, no reports of tsunamis and certainly no reports at this time of any airplane.

Joining me now to try to make sense of all of these latest leads and developments, CNN correspondent and anchor and aviation expert Richard Quest, and also David Soucie, who is a former air accident investigator and author of "Why Planes Crash."

BANFIELD: And the assessor of so many of these facts. (INAUDIBLE) tell us anything, any of what you just heard.

QUEST: Yes, it does because it takes us one small step closer to the facts that we know. So we know that the last known radar and the last known contact was in the South China Seas when there was the handover. And then we get these way points. Let me explain, if I may, about these way points, if that's - if that's -

BANFIELD: Yes, because I have been wondering, who makes them, are they automatic, does everyone know them and are they anything like traveling on land?

QUEST: They're exactly, in a sense, because when you go down an interstate, you get off at a junction. You make a decision to turn off on junction 14 or go to junction 16 and you go to the next place. And what pilots do when they fly is they - here we go. Look at this. So you fly the way point. Now, let's assume -- let's put out for the purposes of argument that this was an intended route, intended. The pilot would have filed a flight plan, an air traffic control -- to go from Malaysia to say the Andaman over here. And in that flight plan, air traffic control would have said -

QUEST: Direction to Gival, on to Egress (ph). And that's what you do. And that's how -- this is nothing unusual. The entire United States is crisscrossed with way points in aviation. And all they've done here is take the ping, they've taken the pings and they've basically said, when you look at the plot, this is what it looks like.

BANFIELD: They're effectively saying pings make it look like this is the route. But, David, is that huge supposition or is this looking pretty plausible?

DAVID SOUCIE, FORMER AVIATION ACCIDENT INVESTIGATOR: It looks plausible to me at this point. You know, we -- to think of where the pings are coming from, we've touched on this before, that it's ACARS, the Aircraft Communication And -

QUEST: Reporting -

SOUCIE: Reporting System. Thank you very much. So the --

BANFIELD: And if you could, for the rest of us who don't live your world, that's the first I've really heard much about ACARS. I don't really understand much about it.

SOUCIE: Yes. ACARS was set up so that the information from the aircraft, maintenance information about engines, the position of aircraft, everything about the position of the aircraft, anything that's going wrong on the aircraft -- there's 10,000 data points per second that are sent through ACARS back to a company called Air Ink (ph). And Air Ink distributes that information to either the airline or to the FAA or to whoever is using that data.

So the curious thing about this though is these - the reason we're calling them pings and not data links is because the ping is saying, I have some data. The aircraft does this, when it loses communication or can't reach anyone, it sends out a ping. It says, where are - where are we and I need to connect with you. So it sends out basically a telephone call waiting for someone to answer. And that's what we're receiving, from what I understand.

BANFIELD: So, first of all, the fact that there are these pings leads me to think that whole notion of a catastrophic disaster in which every single system was destroyed and that's why this thing disappeared isn't quite the case because if there are pings, why are there not transponder information available?

SOUCIE: Exactly. Now there are things that could cause that. I'm not ruling it out. Because if the buses are all lost and the only thing connected to the bus is that transmitter, which is incredibly unlikely. So I would agree with you, that things were intentionally turned off or there was some kind of process, something happened where they were all turned off.

BANFIELD: And you want to add just quickly to this.

QUEST: It's a series of events.

BANFIELD: Yes.

QUEST: The transponder was disabled or failed first. Then you've got the pings.

QUEST: So you've got - you start from the last known position. Then you've got the transponder gets switched off or lost (ph). Transponder information loses. Then you've got the pings. But, don't forget, this pinging stuff, it's not 100 percent accurate. Nobody's saying this is it. They are still having a fairly substantial search on the eastern side of Malaysia into the Gulf of Thailand and down towards the South China Sea.

BANFIELD: All right. So, stand by, if you would, because there are a lot more questions I have. I immediately began thinking about Payne Stewart and this ghost-like flight with everybody in a decompressed airplane effectively asleep or dying while the plane kept flying. And I want to ask about some of the possibilities with respect to this flight in a moment.

David Soucie, thank you. Richard Quest, as always. Stand by for a moment. There are some other big stories that we're following as well.

Because happening right now, two very important men having a very important conversation. Well, listen, they've been nearly constantly talking for several days now, but they can't come up with any way to sort out this Ukraine/Russia mess over Crimea. The American secretary of state, John Kerry, the Russian foreign secretary, Sergey Lavrov, they don't have much longer to negotiate, though, because an independence referendum for Crimea is set for this weekend.

Secretary Kerry is about to address reporters any moment now. Those are live cameras trained in London. And we've been waiting for him to emerge from his meeting with Sergey Lavrov hopefully with some good news. We're standing by on that and we will let you know as soon as we know more.

So what exactly happens inside the cockpit of a plane like the one that vanished? Take a close look at this. It is a flight simulator for the Boeing 777, the same model that the whole world is looking for right now. We're going to take you inside that cockpit live, show you how it works and what might have gone wrong and what, if any, clues we can gain from the simulator.

(COMMERCIAL BREAK)

BANFIELD: I'm about to take you on to the flight deck of a Boeing 777, and it's the exact same type of plane that is right now missing somewhere in Southeast Asia, let's not forget, with 239 people on board. The flight deck, the cockpit, is the part of the aircraft that you are not very likely to see close up for real, unless, as some reports suggest here, a couple of people girls who flirt and take pictures with some of the pilots on the Malaysian airline. That is a whole other conversation.

Instead, Martin Savidge is inside a full-scale, full-motion 777 simulator right now. He joins me live. He's going to show us exactly where those transponders are located and just how easy it is to switch them off, how close they are to the seats where he's sitting right now.

Also with me, in Des Moines, Iowa, is David Funk, the perfect person to talk about in-flight protocols and to ask so many of these what if questions. He's a former airline captain and accident investigator as well.

And still with me, as well, is our own Richard Quest, aviation correspondent and expert.

Martin, I want to begin with you, if I may, because I've been fascinated watching you all morning long as you've sort of recreated the Malaysia Airline Flight 370 flight plan and route. Take it from there and show me what exactly you've been able to determine where you are. MARTIN SAVIDGE, CNN CORRESPONDENT: Right. What we did is we took all the information that was known of the flight, 370. We entered it into this simulator. And now we are flying that path. We are flying at that altitude. We are flying in everything we know in representation to what they did on that night, even including a night sky.

We're, right now, coming up what's called (INAUDIBLE). and if I'm looking at this right, and joining me now is Mitchell Casado, who's the pilot, we're 17.2 nautical miles away. Well, why does that matter? Well, this gets to the way points that Richard Quest was talking about.

And you can see these way points here. They're triangles that are shown here on the navigation map. The pink is the path that we are flying. And BTOD (ph) is the last known official kind of checkpoint in the sky in which 370 radioed in. It was at around that time where they said, "all right, good night," and that's the last officially that was known of the aircraft. So we're just about at that particular moment.

We took off from Kuala Lumpur. We've been flying for about 45 minutes and we're at 35,000 feet on automatic pilot, which is why I'm not touching anything. So, again, all of this exactly from what we know of 370.

The transponder, you talked about. This is a critical piece of equipment. It's right here, right next to me. It looks very small in the relative field of this huge dashboard, but it's so crucially important.

Mitchell, explain what it does, please.

MITCHELL CASADO, PILOT: The transponder is just so that the air traffic controllers on the ground, anyone tracking the plane, can tell where we are, where we came from, where we're going, and our parameters of speed, altitude and heading.

SAVIDGE: And you would not turn it off, but if we think something like that happened, here's how you do it. The switch is right here. It's very small. It is three clicks to the left and, boom, now it is off.

BANFIELD: That's pretty easy.

SAVIDGE: It doesn't mean that this plane has disappeared.

BANFIELD: That's remarkably easy.

SAVIDGE: It is. It is. I mean it's meant to be because why would you turn it off?

CASADO: We have the off switch. The only reason we have the off switch is because when we land, we taxi off the runway. We're no longer a factor for the traffic.

SAVIDGE: So you turn it off because you don't want to be part of the radar system?

CASADO: Exactly, yeah.

SAVIDGE: One other thing -

BANFIELD: Martin?

SAVIDGE: -- to show you with this transponder -- yeah, go ahead, Ashleigh.

BANFIELD: I was going to say, as you show us that next thing with the transponder, Richard Quest has a question for you, as well.

Show what you were showing first and then Richard's going to chime in in a moment.

SAVIDGE: OK. I wanted to just point out that there is a way to use this as kind of an emergency beacon if there is a hijacking of the aircraft. This is widely known. What you can do is you can enter a code.

I'm not going to enter the specific code, but the way it works would be like this. The pilot, co-pilot could enter a code, and then the beacon immediately begins squawking, as they use the term, letting people on the ground know there is a hijack situation.

You'd have alarm bells and red flashers at air controls all around because they now believe they've got a hijack. And you'd probably launch planes to look and investigate.

RICHARD QUEST, CNN CORRESPONDENT: So, Mitchell, it's Richard Quest here. Tell me how easy we can -- we see how easy it is to dismantle or to disable the transponder.

Now give me an idea of how easy it is to disable or disconnect ACARS, or to at least restrict the information that ACARS would send out.

CASADO: ACARS is a system that is a little -- has a bit more to it than the transponder, as far as disabling it.

It is -- it requires very, very in-depth knowledge of the architecture of autopilot and, specifically, the 777, because the 777's the ACARS system is more sophisticated, more advanced than any of those other aircraft, the older generation 76, 75s.

So, whoever is disabling an ACAR system, it's a long process. For someone who knows what they're doing, it can be done, but it's not a simple three-position switch that you're going to be just turning off and on.

QUEST: Exactly. So the fact that this plane stopped -- Martin, the fact that this plane stopped transmitting ACARS data in a series way is significant in that respect, bearing in mind what you're now seeing in the cockpit.

CASADO: Yes, very significant. Couple with the transponder issue, I would say those are the two compelling factors in this incident. I don't want to speculate and say it's an accident, whatever it is, but the fact that those were turned off is a huge warning flag, massive -

BANFIELD: Is a huge factor. OK.

CASADO: -- absolutely no explanation for it.

BANFIELD: So with that in mind, and Mitchell and Martin if you could stand by, don't go away. I want to -- after the break, I want to ask our guest, David Funk, who is a captain and investigator, a security expert, Mr. Funk, if you could -- or Captain Funk, if you could think through the break about everything that we've just been told from that simulator, compare it to the first and early stages of Flight 800, is there any similarity between these two flights?

Are there remarkable differences? Or is there any other thing that tweaked your thought process when you learned at the same time what we were learning?

We're right back after this break.

(COMMERCIAL BREAK)

BANFIELD: I want to bring back David Funk, who I was just asking before the break a significant question about the similarities, if there are any, between the early stages of this flight that we are now searching for and TWA Flight 800.

You were one of the investigators. You're not only a captain. You're an investigator. You're a security expert.

Anything you can compare between these two ill-fated flights?

DAVID FUNK, FORMER PILOT, NORTHWEST AIRLINES: Not really. Other than the ACARS, all communications from TWA 800 were lost when the explosion occurred on the airplane. It severed all the electrical power.

There will be quite a bit of data that will be recovered from this 777 when we ultimately find it.

Believe it or not, on the cockpit voice recorder, which we got a lot of data from that system, because that little microphone acts like a miniature accelerometer, and when you look at that digitally, things the human ear can't pick, there'll be quite a bit of information there as to what happened as far as a shockwave going through the fuselage, as we learned on TWA 800.

The Brits did a lot of extensive testing for the Americans, post-Pan Am 103 and post-TWA 800, to help conduct that investigation.

Oftentimes, the most simple answer here is probably what's happened, and we've heard the Payne Stewart question come up again and again. Was it a depressurization?

I think it's even simpler than that. It may have been something more likely just a minor cockpit fire where the smoke overwhelmed the crew but not before the captain thought I'm going to turn the airplane back towards land, towards the last known point.

He hits the heading bug, spins the airplane around, spins that button back to the west to go towards land. When you're out over water, you want to go towards land. That's a natural human inclination, whether it's a ship captain or an aircraft captain.

And that slow propagating fire disabled the crew and knocked out the systems, one at a time, unlike a -

BANFIELD: Oh, David, I want to think a small fire that at least the cockpit would be equipped with those oxygen masks that we're always trained -

FUNK: It is.

BANFIELD: -- on every flight and they wouldn't -

FUNK: It is.

BANFIELD: have the time? It would be that intense they wouldn't have the time to put on simple oxygen masks so they could at least signal a distress call?

FUNK: It could be, but these things if they propagate slowly, your initial inclination may be, as we've had in many aircraft fires before, you just smell some burning plastic. And if you don't immediately say to yourself, it's 1:30 in the morning, I smell burning plastic, we've got an electrical fire. You order the co-pilot and yourself. You mask up, the first thing you should do.

If that protocol wasn't followed because the guys frankly were tired, it's the middle of the night, that's very possible that they could have been overcome with smoke very quickly.

The fire, what could have caused it? The circuit breaker panels up above your head where the power is controlled --

BANFIELD: Captain Funk, it's the last thing I would think of because, as you just said, it is so simple, Richard Quest, honestly.

QUEST: This is fascinating. This is fascinating.

Captain, I just want to quickly ask you briefly, if I may, Ashleigh, Captain, all this is excellent stuff, but you said right at the last minute, at the last second of your answer there, and all of that, it would have had to have disabled the ACARS because what we got from 447 was these 24 ACARS messages as the plane was in distress and in extremis.

So that has to be part -- assuming we're not talking about the hijacking terrorism scenario, if we're talking mechanical, it has to hit the electrics and the ACAR system.

FUNK: And the ACARS and the transponder are not considered essential components on the airplane. They're not the things you absolutely have to have to navigate and to fly the aircraft. So, they're going to be on a less important electrical bus than the primary communications radios and your navigation equipment and your flight instruments. And, so, when those systems failed, because perhaps there was an electrical fire just in one spot, cockpit fills up with smoke, incipient, comes on slowly.

But when the smoke comes, believe me, a cockpit fills up with smoke very quickly. It's a very small, contained space. These guys could have been incapacitated. The airplane would have flown on for hours based on the fuel.

And getting back to the whole idea of stealing it and flying it, we can lay out literally any track in the world and you will find tens of thousands of waypoints.

If I was going to steal a plane and fly somewhere, I wouldn't go by a route, I would just type in my final destination and that 77 will take me exactly where I want to go, not going over conventional waypoints.

BANFIELD: I want to make sure that our audience is really up to speed. This is very, very arcane stuff, and for people who are hearing about ACARS maybe for the first time, it's an acronym in connection with the plane vanishing.

It's a little confusing, but effectively, it is Aircraft Communication -

FUNK: Very simple.

BANFIELD: -- Addressing and Reporting System. It is pretty simple. I'm putting it up, sort of the ABCs of it, if you will.

It's basically how airplanes communicate directly with people on the ground, but it's not the only way to track a plane. Primary radars show a plane's approximate position, but they don't work once a plane gets a certain distance from land.

Then there are secondary radars that use the plane's transponders. GPS also shows pilots their position, but that information isn't usually shared with air traffic control.

So I just wanted to make sure that, you know, while ACARS is part of --

FUNK: ACARS is real simple.

BANFIELD: It's simple, but for us laypeople --

FUNK: It's a text message system for pilots.

BANFIELD: What's simple for me --

FUNK: Yeah, it's a text message system for pilots.

BANFIELD: True.

FUNK: Exactly. It's just a text message system for pilots.

BANFIELD: So when we come back after the break --

FUNK: That's all it is.

BANFIELD: I have a couple -- I mean, we talked about this yesterday, Richard Quest and I, about how my phone seems so simple and if we only had that for the airplane, it seems that all these very complex systems have certainly failed us in this respect, but what about that Payne Stewart scenario?

What about a massive decompression, a very slow, insidious decompression? Maybe that cockpit fire? Maybe something else like Payne Stewart flying in what effectively became a frozen coffin that just kept flying and flying till it was out of gas?

Is that possible here, especially with the information we have? That story's coming up.